Method and apparatus for continuous mining

ABSTRACT

The mining machine has a pair of rotatable drum members positioned in spaced parallel relation to each other and supported from the mining machine body portion by a pair of forwardly extending support arms. The support arms are pivotally connected to the mining machine and are arranged to move the rotatable drums in a vertical plane. The rotatable drums have a plurality of cutter bits extending radially therefrom to dislodge a pair of parallel kerfs of coal from the face that are slightly wider than the rotatable drum members. The kerfs cut by the rotatable drums extend beyond the side walls of the mining machine. Endless cutter chains with cutting elements thereon are reeved about the drums and the support arms. The endless cutter chains are arranged to dislodge a vertical kerf of coal as the support arms pivot relative to the body portion. A transverse cutter bar is supported within the periphery of the rotatable drum members. The cutter bar has a diameter substantially smaller than the diameter of the rotatable drum members and has radial extending cutter bits thereon along the length thereof to cut a transverse kerf in the coal. Means are provided to rotate the cutter bar relative to the drums to thereby form the transverse kerf between the spaced drum members. Other means are provided to revolve the rotatable cutter bar around the axes of the rotatable drums, so that the cutter bar can be moved to positions tangent to the lower, upper and intermediate portions of the rotatable drum members. The method of continuous mining includes sumping the rotatable cutter drums and transverse cutter bar into the coal and forming a horizontal transverse bottom kerf with the cutter bar and simultaneously forming a pair of vertical side kerfs with the drum member. The horizontal transverse bottom kerf is tangent to the lower edge of the vertical side kerfs. The cutter bar revolves about the axes of the rotatable cutter drum members to a location tangent with the front edge portion of the rotatable cutter drums. The rotatable cutter drums with the transverse cutter bar are is pivoted vertically relative to the mining machine body portion to form a pair of vertical side kerfs. The cutter bar forms a transverse vertical kerf between the vertical side kerf formed by the rotatable drum members. The endless chains form vertical side kerfs as the rotatable drums are pivoted upwardly relative to the mining machine body portion to form continuous vertical side kerfs. The transverse cutter bar is revolved about the axes of the rotatable drum members to a location adjacent the upper portion of the rotatable drum members and the rotatable drum members with the transverse cutter bar intact thereto is sumped rearwardly, completing the vertical side kerfs and a transverse upper horizontal kerf. With this arrangement, a block of coal is dislodged from the face.

United States atent r 91 Galis METHOD AND APPARATUS FOR CONTINUOUS MINING Alex J. Galis, Hetherbrae Square, Apt. 101, Indiana, Pa. 15701 221 Filed: Apr. 7, 1971 21 Appl.No.: 132,093

[76] Inventor:

FOREIGN PATENTS OR APPLICATIONS Primary Examiner-Ernest R. Purser Attorney-Stanley J. Price, Jr.

[5 7 ABSTRACT The mining machine has a pair of rotatable drum members positioned in spaced parallel relation to each other and supported from the mining machine body portion by a pair of forwardly extending support arms. The support arms are pivotally connected to the mining machine and are arranged to move the rotatable drums in a vertical plane. The rotatable drums have a plurality of cutter bits extending radially therefrom to dislodge a pair of parallel kerfs of coal from the face that are slightly wider than the rotatable drum members. The kerfs cut by the rotatable drums extend Poland ..299/65 [111 3,726,563 [451 Apr. 10, 1973 beyond the side walls of the mining machine. Endless cutter chains with cutting elements thereon are reeved about the drums and the support arms. The endless cutter chains are arranged to dislodge a vertical kerf of coal as the support arms pivot relative to the body portion. A transverse cutter bar is supported within the periphery of the rotatable drum members. The cutter bar has a diameter substantially smaller than the diameter of the rotatable drum members and has radial extending cutter bits thereon along the length thereof to cut a transverse kerf in the coal. Means are provided to rotate the cutter bar relative to the drums to thereby form the transverse kerf between the spaced drum members. Other means are provided to revolve the rotatable cutter bar around the axes of the rotatable drums, so that the cutter bar can be moved to positions tangent to the lower, upper and intermediate portions of the rotatable drum members. The method of continuous mining includes sumping the rotatable cutter drums and transverse cutter bar into the coal and forming a horizontal transverse bottom kerf with the cutter bar and simultaneously forming a pair of vertical side kerfs with the drum member. The horizontal transverse bottom kerf is tangent to the lower edge of the vertical side kerfs. The cutter bar revolves about the axes of the rotatable cutter drum members to a location tangent with the front edge portion of the rotatable cutter drums. The rotatable cutter drums with the transverse cutter bar are is pivoted verticallyYel ativet6 tEnifil g rnachine body portion to form a pair of vertical side kerfs. The cutter bar forms a transverse vertical kerf between the vertical side kerf formed by the rotatable drum members. The endless chains form vertical side kerfs as the rotatable drums are pivoted upwardly relative to the mining machine body portion to form continuous vertical side kerfs. The transverse cutter bar is revolved about the axes of the rotatable drum members to a location adjacent the upper portion of the rotatable drum members and the rotatable drum members with the transverse cutter bar intact thereto is sumped rearwardly, completing the vertical side kerfs and a transverse upper horizontal kerf. With this arrangement, a block of coal is dislodged from the face.

14 Claims, 9-Drawing Figures 11] mm III u: I IIIIIIUIIIII H ll-i PATENTED APR 1 0 ms SHEET 2 or INVENTOR ALEX J. GALIS 5M7 J P L HIS ATTORNEY.

PATENTED 1 019,75

SHEET 3 [1F 3 INVENTOR. EX J. GALIS,

is ATTORNEY,

METHOD AND APPARATUS FOR CONTINUOUS MINING BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a method and apparatus for continuous mining and more particularly to a mining machine that includes a pair of spaced drums with a 1 transverse cutter bar therebetween.

2. Description of the Prior Art Drum type mining machines are known as, for example, the drum type mining machine illustrated in U.S. Pat. Nos. 3,499,684 and 3,353,871. Scrolled type mining machines that include a transverse cutter bar having scroll type cutting means thereon are also known, as is illustrated in US. Pat. No. 3,088,718. Mining machines having side swing type cutter drums and chains are also known as, for example, the mining machine illustrated in US. Pat. No. 3,210,123. All of these types of mining machines dislodge the coal by a picking action of the cutter bits to break small particles of the coal away from the face. Dislodging coal in this manner requires a substantial amount of energy to dislodge the relatively small coal particles. It is well ,known that the coal at the face has substantial pressures exerted thereon so that any forces exerted on the coal from behind the face will dislodge the coal with less energy than the picking action of the cutter bits advancing directly into the mine face.

SUMMARY OF THE INVENTION This invention relates to a method and apparatus for continuous mining in which the cutting elements are advanced behind the coal face to dislodge the coal. The mining machine includes a pair of spaced rotatable drums pivotally supported by arm members from the front end of the mining machine body portion. A transverse cutter bar extends between the rotatable drums and is rotatable with the rotatable drums. The transverse cutter bar is arranged to revolve about the axes of the rotatable drums to be positioned substantially tangent to the upper, lower and intermediate portions of the drum peripheries. Endless cutter chains are reeved about the rotatable drum members and the support arms. With this arrangement, the transverse bar is revolved about the rotatable drum member axes to a location substantially tangent to the lower portion of the rotatable drum members. The mining machine rotatable drums pivoted downwardly are sumped into the coal face to form a longitudinal transverse kerf by the transverse cutter bar and a pair of vertical side kerfs having a dimension substantially equal to the diameter of the drums. After the mining machine is advanced into the face a preselected distance, the transverse cutter bar is revolved forwardly about the axes of the rotatable drums to an intermediate location to form an arcuate transverse kerf that connects with the lower transverse kerf previously formed. The rotatable drums with the transverse cutter bar therebetween are pivoted upwardly into a preselected elevation. With this upward movement of the vertical drums and transverse cutter bar, a vertical kerf is formed by the cutter bar and a pair of side vertical kerfs having a dimension substantially equal to the diameter of the rotatable drums is formed. The transverse cutter bar is thereafter revolved about the axes of the rotatable drum members to a location substantially tangent to the upper periphery of the rotatable drums to form an arcuate transverse kerf connected to the vertical transverse kerf previously formed. The mining machine is thereafter sumped rearwardly to form an upper transverse kerf by the transverse cutter bar and a pair of vertical side kerfs with dimensions substantially equal to 0 the dimension of the rotatable cutter drums when the drums are moved vertically a dimension greater than the diameter of the drums. The endless cutter chains cut a vertical kerf between the vertical side kerfs formed by the rotatable drums to therefore dislodge a block of coal from the face.

Accordingly, the principal object of this invention is to provide a method for dislodging coal by forming a vertical kerf behind the coal face and horizontal upper and lower kerfs connected to the vertical kerf.

Another object of this invention is to provide a method and apparatus for continuous mining by dislodging coal from behind the coal face.

These and other objects and advantages of this invention will be more completely disclosed and described in the following specification, the accompanying drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary plan view of the front end of my improved mining machine illustrating the pair of spaced rotatable drums with the transverse cutter bar therebetween.

FIG. 2 is a view in section taken along the lines 11-1] of FIG. 1 illustrating the relative position of the transverse cutter bar within one of the rotatable drums and the manner in which the transverse cutter bar is driven by the rotatable drum.

FIG. 3 is a schematic elevation in section of the mining machine illustrated in FIG. I dislodging a block of coal from a coal seam.

FIG. 4 is a view in section similar to FIG. 3 illustrating the manner in which a block of coal may be removed from a coal seam by the embodiment illustrated in FIGS. 5-9.

FIG. 5 is a top plan view of another embodiment of my improved mining machine illustrating a plurality of transverse cutter chains reeved about the rotatable drums.

FIG. 6 is a view in side elevation taken along the line VI-VI of FIG. 5 illustrating the support means for the rotatable drum.

FIG. 7 is a fragmentary view in section of one of the rotatable drums illustrated in FIG. 5 illustrating the apparatus for revolving the transverse cutter bar within the rotatable drum.

FIG. 8 is a view in section taken along the line VIII- VIII of FIG. 7 illustrating the drive arrangement for the transverse cutter bar.

FIG. 9 is a view in perspective of the mining machine from end portion illustrated in FIGS. 5 and 6.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to FIGS. 5-9 there is illustrated a miming machine generally designated by the numeral 10 that has a body portion 12 with side walls 14 and 16 and a front end wall 18. The body portion 12 is mounted on a pair of endless track propelling devices 20 that are arranged to propel the mining machine within the mine and also to advance and retract the mining portion of the machine as later described.

The mining machine 10 has material dislodging apparatus generally designated by the numeral 22 suitably mounted on the front end of the body portion 12. The material dislodging apparatus 22 includes a pair of side arm members 24 and 26. The front end portion of arms 24 and 26 has a clevis or U-shaped portion 28 arranged to support a housing 30 for the rotatable drum mounted thereon. The arms 24 have an inturned offset portion 32 that terminates in an end portion 34. The end portion 34 has an aperture 36 therethrough, through which a rotatable shaft 38 extends.

The shaft 38 is rotatably mounted on the front end of the mining machine body portion 12 by pillow block type bearings 40 so that the rotatable shaft 38 extends substantially parallel to the mining machine body portion front end wall 18. A pair of drum-like sprockets 42 and 44 are mounted on the ends of rotatable shaft 38 for rotation therewith. A drive motor 46 is mounted in the mining machine body portion and is drivingly connected through sprocket 48, chain 50 and sprocket 52 to the shaft 38. With this arrangement, drive motor 46 rotates the shaft 38 at a preselected speed and the shaft, in turn, rotates the sprockets 42 and 44 connected to the ends thereof.

The side arms 24 and 26'support housings 30 for a pair of rotatable drums 54 and 56. The drums have a plurality of radially extending cutter bits 58 thereon and a plurality of spaced sprocket teeth 60. The drums 54 and 56 have a central inwardly extending portion 62 with inner gear teeth 64 thereon. The drums 54 and 56 are rotatably mounted on the housings 30 with bearings 66 therebetween so that the rotatable drums 54 and 56 are arranged to rotate relative to the housings 30 and the clevis portion 28.

A plurality of endless chains 68, 70, 72 and 74 are reeved about the sprockets 42 secured to rotatable shaft 38 and about the drum 54 in spaced parallel relation to each other. The endless chains 68, 70, 72 and 74 have cutter bits 76 extending outwardly therefrom and the chains 68 and 74 have cutter bits extending transversely therefrom. Similarly, a plurality of endless chains 7 8, 80, 82 and 84 are reeved about the sprockets 44 mounted on drive shaft 38 and about the drum 56 supported by arm 26. The support for the drum 56 from arm 26 is substantially the same as that for drum 54, previously described. With this arrangement the drive motor 46 through chain 50 rotates rotatable shaft 38 which, in turn, rotates sprockets 42 and 44 mounted thereon. The chains 68, 70, 72 and 74 are driven by the sprockets 42 to thus rotate drum 54. Similarly, chains 78, 80, 82 and 84 are driven by sprockets 44 and, in turn, rotate the drum 56.

Referring now to FIG. 8, the drum 54 has an inwardly extending annular portion 62 with gear teeth thereon. There is an axial gear 86 rotatably supported on shaft 88 which is, in turn, supported by housing 30 and arm 28. The axial gear 86 is freely rotatable relative to the drum 54. A planet gear 90 meshes with the gear teeth 64 of inwardly extending annular portion 62 of drum 54 and the external teeth of axial gear 86. The

planet gear is nonrotatably secured to a cutter bar shaft end portion 92. Positioned between the drums 54 and 56 and extending transversely thereof is a rotatable cutter bar 94 that has shaft end portions 96 and 92. The shaft end portion 92, as previously described, has the planet gear 90 nonrotatably mounted thereon. The shaft end portion 96 has a similar planet gear mounted thereon within the drum 56. With this arrangement the rotation of drums 54 and 56 is transmitted through the gear teeth 64 of inwardly extending portion 62 to the planet gears 90 mounted on the cutter bar shaft endportions 92 and 96 to thus transmit rotation to the cutter bar 94. Because of the gear ratio, the cutter bar 94 rotates at a substantially higher speed than the drums 54 and 56. There are a plurality of cutter bits 98 extending radially from the cutter bar to dislodge coal upon rotation of cutter bar 94.

The side arms 24 and 26 are thus pivotally supported by the rotatable shaft 38 so that the drums 54 and 56 may be moved in an arcuate path about the axis of shaft 38. The relative position of the side arms 24 and 26 is controlled by piston cylinder mechanism 100 and 102 pivotally connected at one end to the mining machine body portion and at the other end to a plate 104 connected to the respective arms. Thus, upon extension of the piston rods within the piston cylinder mechanisms 100 and 102, the arms 24 and 26 are pivoted downwardly to move the drums 54 and 56 toward the ground or floor designated by the numeral 106. Upon retraction of the piston within the piston cylinder mechanisms 100 and 102 the arms 24 and 26 pivot to raise the drums 54 and 56 as illustrated in FIG. 6.

Control arms 108 and 110 have end portions 112 and 114 with apertures therein. The cutter bar shaft end portions 92 and 96 extend through the apertures in the control arm end portions 112 and 114. The control arms 108 and 110 are connected at their opposite end to the side arms 24 and 26 by means ofpin type connections 116 and 118. The control arms 108 and 110 have an intermediate tubular portion 120 with inwardly extending splines that mate with outwardly extending splines on portions of the arms 108 and 110 to thus permit the arms to increase and decrease in effective length. The intermediate tubular portions 120 are connected to rods 122 of other piston cylinder mechanisms 124 and 126. With this arrangement the piston cylinder mechanisms 124 and 126 control the relative position of the rotatable cutter bar 94 within the periphery of the drums 54 and S6.

Referring now to FIG. 4, the manner in which the previously described mining machine 10 dislodges a block of coal from a mine seam is as follows. The piston cylinder mechanisms 100 and 102 are actuated to extend the piston rods and pivot the arm members 24 and 26 downwardly until the drums 54 and 56 are adjacent the floor 106, as is indicated by the letter A in FIG. 4. The piston cylinder mechanisms 124 and 126 are actuated to move the cutter bar 24 to the lower quadrant of drums 54 and 56 substantially tangent to the floor 106 as illustrated in FIG. 4 and designated by the letter B. The motor 46 is then actuated to rotate both the cutter drums 54 and 56 and, in turn, the cutter bar 94. The drums 54 and 56 form a pair of side kerfs in the coal seam having a dimension substantially equal to the diameter of the drums. The rotatable cutter bar 94 forms a transverse kerf adjacent the floor 106 having a dimension substantially equal to the dimension of the cutter bar and the radial dimension of the cutter teeth mounted thereon. The endless track propelling devices are then actuated to advance the mining machine into the coal seam a preselected distance as, for example, to the location indicated by the letter C for the drums 54 and 56. At this location the piston cylinder mechanisms 24 and 26 are actuated to revolve the cutter bar 94 relative to the drums 54 and 56 to move the drums forwardly to a position substantially tangent to the front portion of the drums 54 and 56, as is indicated by the letter D in FIG. 4. The piston cylinder mechanisms 100 and 102 are then actuated to pivot the drums 54 and 56 upwardly and form a pair of vertical side kerfs of substantially the thickness of the drums. The cutter bar 94, in turn, is cutting a transverse kerf from the lower transverse kerf upwardly to the location indicated by the letter E in FIG. 4. At the elevation indicated by the letter E the piston cylinder mechanism 124 and 126 revolve the cutter bar within the drums 54 and S6 to a location substantially tangent to the upper portion of drums 54 and 56, as indicated by the letters F and G in FIG. 4. At this location the endless track propelling devices 20 move the mining machine rearwardly while rearwardside kerfs are formed in the seam by the drums 54 and 56 and a transverse kerf is formed by the cutter bar 94 to thereby dislodge a block of coal designated by the letter R. The endless chains 68, 70, 72 and 74 and 78, 80, 82 and 84 complete the side kerfs formed by drums 54 and 56 between the lower and upper elevations of the drums to provide two continuous side kerfs to thereby completely dislodge the block of coal II. It should be understood that although reference is made to the mining of coal in this specification, the apparatus described in this specification is also suitable for dislodging other material from underground seams. It should also be understood that the previously described apparatus may be employed to dislodge smaller or larger blocks of material from the seam or to advance into the seam a depth substantially equal to or less than the diameter of the drums 54 and 56 and to then sump the drums and transverse cutter bar upwardly or downwardly to dislodge coal from the seam. One of the features of the apparatus herein described is the revolving of the cutter bar 94 around the axis of the drums S4 and 56.

Now referring to FIGS. 1 and 2, another embodiment of the invention is illustrated and portions of the apparatus previously described for controlling the relative position of the drums and the cutter bar have been omitted to more clearly illustrate the embodiment shown in FIGS. 1 and 2. It should be understood, however, that the actuating mechanisms such as piston cylinder mechanisms 100, 102 and 124, 126 or other mechanisms for performing substantially the same functions may be employed with the embodiment illustrated in FIGS. 1 and 2.

Referring to FIGS. 1 and 2, similar numerals will designate similar previously described parts of the mining machine. The drums 54 and 56 both have a pair of chains 128 and 130 reeved therearound and around sprockets 132 and 134. The drums 54 and 56 are supported in a manner similar to that illustrated in FIG. 5 and the sprockets 132 and 134 are driven by motors 136 and 138. The rotary cutter bar 94 is arranged to rotate with the drums 54 and 56 and is driven in a manner previously described. The pair of chains 128 and that rotate the drums 54 and 56 do not complete the vertical side kerf as the plurality of cutter chains described and illustrated in FIG. 5. The mining machine illustrated in FIGS. 1 and 2 is arranged to dislodge blocks of coal of the dimensions illustrated in FIG. 3 in a manner similar to that previously described. It should be noted, however, that the mining machine advances into the seam a preselected distance and the drums 54 and 56 are then pivoted to an elevation where the drums slightly overlap the side kerf formed by the advance of the mining machine. Prior to moving the drums vertically, the cutter bar 94 is revolved about the axis of the drums as previously described to a location substantially tangent to the front edge of the drums. After the drums have been pivoted to the elevation where they slightly overlap the side kerfs formed by the advance of the mining machine, the cutter bar 94 is again revolved to a location where it is substantially tangent to the top portion of the drums. Thereafter, the mining machine is moved rearwardly to increase the height of the side kerfs and to form the transverse kerf by the cutter bar 94, dislodging a block of coal therefrom, as is illustrated in-FIG. 3. The depth at which the drums and transverse cutter bar are advanced into the seam may be changed to obtain different sized mined material and the chains in the embodiment illustrated in FIGS. 1 and 2 do not require cutter bits thereon.

According to the provisions of the patent statutes, I

have explained the principle, preferred construction, and mode of operation of my invention and have illustrated and described what I now consider to represent its best embodiments. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

I claim:

1. A mining machine comprising,

a body portion having a pair of arm members pivotally secured thereto and extending forwardly therefrom, said arm members arranged in spaced parallel relation to each other,

drum members rotatably mounted on the front end of said arm members with the axes of said drum members extending horizontally,

cutting means positioned on the outer periphery of said drum members and extending radially therefrom so that upon rotation said drum members dislodge vertical kerfs having a height substantially the same as the diameter of said drum members with said cutting .means extending therefrom,

a transverse cutter bar rotatably supported in said drum member and extending transversely therebetween, the axis of said transverse cutter bar being parallel to the axis of said drum member,

said cutter bar having a diameter substantially smaller than the diameter of said drum members,

means to rotate said drum members at a first selected speed and to rotate said transverse cutter bar at a second selected speed, said second selected speed of said transverse cutter bar being greater than said first selected speed of said drum members, and other cutting means positioned on the outer periphery of said transverse cutter bar so that, upon rotation, said transverse cutter bar dislodges a horizontal kerf between said vertical kerfs formed by said drum members, said horizontal kerf having a diameter substantially the same as the diameter of said transverse cutter bar with said cutting means extending radially therefrom.

2. A mining machine as set forth in claim 1 which includes,

means to revolve said transverse cutter bar about the axis of said drum cutters to thereby position said transverse cutter bar at different elevations relative to the axes of said drum members.

3. A mining machine as set forth in claim 1 which includes,

sprocket members rotatably supported on said arm members adjacent said mining machine body portion,

said drum members including other sprocket members,

endless chains reeved about said sprocket members rotatably supported adjacent the mining machine body portion and said other sprocket members on said drum members,

other cutting means extending outwardly from said endless chains.

4. A mining machine as set forth in claim 1 which includes means to pivot said drum members vertically relative to said mining machine body portion.

5. A method of mining comprising,

advancing a mining machine having a pair of spaced horizontal drums with a transverse horizontal cutter bar therebetween into a mine face, said drum members having horizontally extending axes, said cutter bar having a diameter smaller than the diameter of said horizontal drums,

rotating said horizontal drums and said transverse horizontal cutter bar with said transverse horizontal cutter bar rotating at a speed greater than the speed of said horizontal drums, forming a first pair of spaced vertical side kerfs in the face with said horizontal drums and a horizontal transverse kerf therebetween with said transverse horizontal cutter bar, A

moving said horizontal drums and transverse horizontal cutter bar upwardly in said mine face to form a second pair of spaced vertical side kerfs by said horizontal drums connected to said first pair of vertical side kerfs and a second horizontal transverse kerf connected to said first horizontal kerf,

retracting said mining machine and forming a third pair of spaced vertical side kerfs by said horizontal drums and a third horizontal transverse kerf, said third pair of spaced vertical side kerfs connected to said second pair of spaced vertical side kerfs and said third horizontal transverse kerf connected to said second horizontal transverse kerf to thereby dislodge a generally rectangular portion of material from the face.

6. A method of mining as set forth in claim 5 in which said horizontal transverse kerfs have a diameter substantially smaller than the diameter of said vertical side kerfs.

7. A method of mining as set forth in claim 5 which includes revolving said transverse horizontal cutter bar about the axes of said horizontal drums to thereby form said first horizontal transverse kerf substantially tangent to the lower periphery of said spaced vertical side kerfs.

8. A method of mining as set forth in claim 5 in which said first and third pair of vertical side kerfs are spaced vertically from each other and,

connecting said first and third vertical side kerfs with other vertical side kerfs.

9. A mining machine comprising,

a body portion having a pair of arm members pivotally secured thereto and extending forwardly therefrom, said arm members arranged in spaced parallel relation to each other,

drum members rotatably mounted on the front end of said arm members with the axes of said drum members extending horizontally,

cutting means positioned on the outer periphery of said drum members and extending radially therefrom so that upon rotation said drum members dislodge vertical kerfs having a height substantially the same as the diameter of said drum members with said cutting means extending therefrom,

a transverse cutter bar rotatably supported in said drum member and extending transversely therebetween, the axis of said transverse cutter bar being parallel to the axis of said drum member,

said cutter bar having a diameter substantially smaller than the diameter of said drum members,

means to revolve said transverse cutter bar about the axis of said drum cutters to thereby position said transverse cutter bar at different elevations relative to the axes of said drum members, and

other cutting means positioned on the outer periphery of said transverse cutter bar so that, upon rotation, said transverse cutter bar dislodges a horizontal kerf between said vertical kerfs formed by said drum members, said horizontal kerf having a diameter substantially the same as the diameter of said transverse cutter bar with said cutting means extending radially therefrom.

10. A mining machine as set forth in claim 9 which includes,

means to rotate said drum members at a first selected speed and to rotate transverse 'cutter bar at a second selected speed, said second selected speed of said transverse cutter bar being greater than said first selected speed of said drum members.

11. A mining machine as set forth in claim 9 which includes,

sprocket members rotatably supported on said arm members adjacent said mining machine body portion, said drum members including other sprocket members, endless chains reeved about said sprocket members rotatably supported adjacent the mining machine body portion and said other sprocket members on said drum members, other cutting means extending outwardly from said endless chains. 12. A mining machine comprising,

a body portion having a pair of arm members pivotally secured thereto and extending forwardly therefrom, said arm members arranged in spaced parallel relation to each other,

drum members rotatably mounted on the front end of said arm members with the axes of said drum members extending horizontally,

cutting means positioned on the outer periphery of said drum members and extending radially therefrom so that upon rotation of said drum members dislodge vertical kerfs having a height substantially the same as the diameter of said drum members with said cutting means extending therefrom,

a transverse cutter bar rotatably supported in said drum member and extending transversely therebetween, the axis of said transverse cutter bar being parallel to the axis of said drum member,

said cutter bar having a diameter substantially smaller than the diameter of said drum members,

other cutting means positioned on the outer periphery of said transverse cutter bar so that, upon rotation, said transverse cutter bar dislodges a horizontal kerf between said vertical kerfs formed by said drum members, said horizontal kerf having a diameter substantially the same as body portion and said sprocket members on said drum members,

cutting means extending outwardly from said endless chains.

13. A mining machine as set forth in claim 12 which includes,

means to rotate said drum members at a first selected speed and to rotate said transverse cutter bar at a second selected speed, said second selected speed of said transverse cutter bar being greater than said first selected speed of said drum members.

14. A mining machine as set forth in claim 12 which includes,

means to revolve said transverse cutter bar about the axis of said drum cutters to thereby position said transverse cutter bar at different elevations relative to the axes of said drum members. 

1. A mining machine comprising, a body portion having a pair of arm members pivotally secured thereto and extending forwardly therefrom, said arm members arranged in spaced parallel relation to each other, drum members rotatably mounted on the front end of said arm members with the axes of said drum members extending horizontally, cutting means positioned on the outer periphery of said drum members and extending radially therefrom so that upon rotation said drum members dislodge vertical kerfs having a height substantially the same as the diameter of said drum members with said cutting means extending therefrom, a transverse cutter bar rotatably supported in said drum member and extending transversely therebetween, the axis of said transverse cutter bar being parallel to the axis of said drum member, said cutter bar having a diameter substantially smaller than the diameter of said drum members, means to rotate said drum members at a first selected speed and to rotate said transverse cutter bar at a second selected speed, said second selected speed of said transverse cutter bar being greater than said first selected speed of said drum members, and other cutting means positioned on the outer periphery of said transverse cutter bar so that, upon rotation, said transverse cutter bar dislodges a horizontal kerf between said vertical kerfs formed by said drum members, said horizontal kerf having a diameter substantially the same as the diameter of said transverse cutter bar with said cutting means extending radially therefrom.
 2. A mining machine as set forth in claim 1 which includes, means to revolve said transverse cutter bar about the axis of said drum cutters to thereby position said transverse cutter bar at different elevations relative to the axes of said drum members.
 3. A mining machine as set forth in claim 1 which includes, sprocket members rotatably supported on said arm members adjacent said mining machine body portion, said drum meMbers including other sprocket members, endless chains reeved about said sprocket members rotatably supported adjacent the mining machine body portion and said other sprocket members on said drum members, other cutting means extending outwardly from said endless chains.
 4. A mining machine as set forth in claim 1 which includes means to pivot said drum members vertically relative to said mining machine body portion.
 5. A method of mining comprising, advancing a mining machine having a pair of spaced horizontal drums with a transverse horizontal cutter bar therebetween into a mine face, said drum members having horizontally extending axes, said cutter bar having a diameter smaller than the diameter of said horizontal drums, rotating said horizontal drums and said transverse horizontal cutter bar with said transverse horizontal cutter bar rotating at a speed greater than the speed of said horizontal drums, forming a first pair of spaced vertical side kerfs in the face with said horizontal drums and a horizontal transverse kerf therebetween with said transverse horizontal cutter bar, moving said horizontal drums and transverse horizontal cutter bar upwardly in said mine face to form a second pair of spaced vertical side kerfs by said horizontal drums connected to said first pair of vertical side kerfs and a second horizontal transverse kerf connected to said first horizontal kerf, retracting said mining machine and forming a third pair of spaced vertical side kerfs by said horizontal drums and a third horizontal transverse kerf, said third pair of spaced vertical side kerfs connected to said second pair of spaced vertical side kerfs and said third horizontal transverse kerf connected to said second horizontal transverse kerf to thereby dislodge a generally rectangular portion of material from the face.
 6. A method of mining as set forth in claim 5 in which said horizontal transverse kerfs have a diameter substantially smaller than the diameter of said vertical side kerfs.
 7. A method of mining as set forth in claim 5 which includes revolving said transverse horizontal cutter bar about the axes of said horizontal drums to thereby form said first horizontal transverse kerf substantially tangent to the lower periphery of said spaced vertical side kerfs.
 8. A method of mining as set forth in claim 5 in which said first and third pair of vertical side kerfs are spaced vertically from each other and, connecting said first and third vertical side kerfs with other vertical side kerfs.
 9. A mining machine comprising, a body portion having a pair of arm members pivotally secured thereto and extending forwardly therefrom, said arm members arranged in spaced parallel relation to each other, drum members rotatably mounted on the front end of said arm members with the axes of said drum members extending horizontally, cutting means positioned on the outer periphery of said drum members and extending radially therefrom so that upon rotation said drum members dislodge vertical kerfs having a height substantially the same as the diameter of said drum members with said cutting means extending therefrom, a transverse cutter bar rotatably supported in said drum member and extending transversely therebetween, the axis of said transverse cutter bar being parallel to the axis of said drum member, said cutter bar having a diameter substantially smaller than the diameter of said drum members, means to revolve said transverse cutter bar about the axis of said drum cutters to thereby position said transverse cutter bar at different elevations relative to the axes of said drum members, and other cutting means positioned on the outer periphery of said transverse cutter bar so that, upon rotation, said transverse cutter bar dislodges a horizontal kerf between said vertical kerfs formed by said drum members, said horizontal kerf having a diameter substantially the same as the diameter of said transverse cutter bar witH said cutting means extending radially therefrom.
 10. A mining machine as set forth in claim 9 which includes, means to rotate said drum members at a first selected speed and to rotate transverse cutter bar at a second selected speed, said second selected speed of said transverse cutter bar being greater than said first selected speed of said drum members.
 11. A mining machine as set forth in claim 9 which includes, sprocket members rotatably supported on said arm members adjacent said mining machine body portion, said drum members including other sprocket members, endless chains reeved about said sprocket members rotatably supported adjacent the mining machine body portion and said other sprocket members on said drum members, other cutting means extending outwardly from said endless chains.
 12. A mining machine comprising, a body portion having a pair of arm members pivotally secured thereto and extending forwardly therefrom, said arm members arranged in spaced parallel relation to each other, drum members rotatably mounted on the front end of said arm members with the axes of said drum members extending horizontally, cutting means positioned on the outer periphery of said drum members and extending radially therefrom so that upon rotation of said drum members dislodge vertical kerfs having a height substantially the same as the diameter of said drum members with said cutting means extending therefrom, a transverse cutter bar rotatably supported in said drum member and extending transversely therebetween, the axis of said transverse cutter bar being parallel to the axis of said drum member, said cutter bar having a diameter substantially smaller than the diameter of said drum members, other cutting means positioned on the outer periphery of said transverse cutter bar so that, upon rotation, said transverse cutter bar dislodges a horizontal kerf between said vertical kerfs formed by said drum members, said horizontal kerf having a diameter substantially the same as the diameter of said transverse cutter bar with said cutting means extending radially therefrom, and sprocket members rotatably supported on said arm members adjacent said mining machine body portion, said drum members including sprocket members, endless chains reeved about said sprocket members rotatably supported adjacent the mining machine body portion and said sprocket members on said drum members, cutting means extending outwardly from said endless chains.
 13. A mining machine as set forth in claim 12 which includes, means to rotate said drum members at a first selected speed and to rotate said transverse cutter bar at a second selected speed, said second selected speed of said transverse cutter bar being greater than said first selected speed of said drum members.
 14. A mining machine as set forth in claim 12 which includes, means to revolve said transverse cutter bar about the axis of said drum cutters to thereby position said transverse cutter bar at different elevations relative to the axes of said drum members. 